Allow overriding otel exporter and extension configuration for outputs

internal/pkg/otel/translate/otelconfig.go

@@ -36,7 +36,13 @@ import (
 
 // This is a prefix we add to all names of Otel entities in the configuration. Its purpose is to avoid collisions with
 // user-provided configuration
-const OtelNamePrefix = "_agent-component/"
+const (
+	OtelNamePrefix                        = "_agent-component/"
+	BeatsAuthExtensionType                = "beatsauth"
+	outputOtelOverrideFieldName           = "otel"
+	outputOtelOverrideExporterFieldName   = "exporter"
+	outputOtelOverrideExtensionsFieldName = "extensions"
+)
 
 // BeatMonitoringConfigGetter is a function that returns the monitoring configuration for a beat receiver.
 type (
@@ -183,7 +189,7 @@ func getExporterID(exporterType otelcomponent.Type, outputName string) otelcompo
 // outputName here is name of the output defined in elastic-agent.yml. For ex: default, monitoring
 func getBeatsAuthExtensionID(outputName string) otelcomponent.ID {
 	extensionName := fmt.Sprintf("%s%s", OtelNamePrefix, outputName)
-	return otelcomponent.NewIDWithName(otelcomponent.MustNewType("beatsauth"), extensionName)
+	return otelcomponent.NewIDWithName(otelcomponent.MustNewType(BeatsAuthExtensionType), extensionName)
 }
 
 // getCollectorConfigForComponent returns the Otel collector config required to run the given component.
@@ -426,6 +432,12 @@ func unitToExporterConfig(unit component.Unit, exporterType otelcomponent.Type,
 		return nil, nil, nil, fmt.Errorf("error translating config for output: %s, unit: %s, error: %w", outputName, unit.ID, err)
 	}
 
+	// if there's an otel override config, extract it, we'll apply it after the conversion
+	otelOverrideCfgC, err := extractOutputOtelOverrideConfig(outputCfgC)
+	if err != nil {
+		return nil, nil, nil, err
+	}
+
 	// Config translation function can mutate queue settings defined under output config
 	exporterConfig, err := configTranslationFunc(outputCfgC, logger)
 	if err != nil {
@@ -443,6 +455,19 @@ func unitToExporterConfig(unit component.Unit, exporterType otelcomponent.Type,
 		}
 	}
 
+	// if there's an otel override section for the exporter, we should apply it
+	exporterOverrideCfg, err := getOutputOtelOverrideExporterConfig(otelOverrideCfgC)
+	if err != nil {
+		return nil, nil, nil, err
+	}
+	koanfmaps.Merge(exporterOverrideCfg, exporterConfig)
+
+	// if there's an otel override section for extensions, extract it and apply it to individual extension configs
+	extensionsOverrideCfg, err := getOutputOtelOverrideExtensionsConfig(otelOverrideCfgC)
+	if err != nil {
+		return nil, nil, nil, err
+	}
+
 	// beatsauth extension is not tested with output other than elasticsearch
 	if exporterType.String() == "elasticsearch" {
 		// get extension ID
@@ -452,6 +477,10 @@ func unitToExporterConfig(unit component.Unit, exporterType otelcomponent.Type,
 			return nil, nil, nil, fmt.Errorf("error supporting http parameters for output: %s, unit: %s, error: %w", outputName, unit.ID, err)
 		}
 
+		if beatsauthOverrideCfg, found := extensionsOverrideCfg[BeatsAuthExtensionType]; found {
+			koanfmaps.Merge(beatsauthOverrideCfg, extensionConfig)
+		}
+
 		// sets extensionCfg
 		extensionCfg = map[string]any{
 			extensionID.String(): extensionConfig,
@@ -519,16 +548,74 @@ func translateEsOutputToExporter(cfg *config.C, logger *logp.Logger) (map[string
 	if err != nil {
 		return nil, err
 	}
-	// dynamic indexing works by default
 
-	// we also want to use dynamic log ids
+	// we want to use dynamic log ids
 	esConfig["logs_dynamic_id"] = map[string]any{"enabled": true}
 
 	esConfig["include_source_on_error"] = true
 
 	return esConfig, nil
 }
 
+// extractOutputOtelOverrideConfig removes the configuration under the otel override key from the provided configuration
+// and returns it.
+func extractOutputOtelOverrideConfig(cfg *config.C) (*config.C, error) {
+	if !cfg.HasField(outputOtelOverrideFieldName) {
+		return nil, nil
+	}
+	otelCfg, err := cfg.Child(outputOtelOverrideFieldName, -1)
+	if err != nil {
+		return nil, err
+	}
+	_, err = cfg.Remove(outputOtelOverrideFieldName, -1)
+	if err != nil {
+		return nil, err
+	}
+	return otelCfg, nil
+}
+
+// getOutputOtelOverrideExporterConfig returns the exporter override configuration from the given otel override
+// configuration as a map[string]any. It does not modify the input.
+func getOutputOtelOverrideExporterConfig(otelOverrideCfg *config.C) (map[string]any, error) {
+	if otelOverrideCfg == nil {
+		return nil, nil
+	}
+	if !otelOverrideCfg.HasField(outputOtelOverrideExporterFieldName) {
+		return nil, nil
+	}
+	exporterCfgC, err := otelOverrideCfg.Child(outputOtelOverrideExporterFieldName, -1)
+	if err != nil {
+		return nil, err
+	}
+	exporterCfgMap := make(map[string]any)
+	err = exporterCfgC.Unpack(&exporterCfgMap)
+	if err != nil {
+		return nil, err
+	}
+	return exporterCfgMap, nil
+}
+
+// getOutputOtelOverrideExporterConfig returns the override configuration for extensions from the given otel override
+// configuration. The return value is a map keyed by extension types, with configuration overrides as values.
+func getOutputOtelOverrideExtensionsConfig(otelOverrideCfg *config.C) (map[string]map[string]any, error) {
+	if otelOverrideCfg == nil {
+		return nil, nil
+	}
+	if !otelOverrideCfg.HasField(outputOtelOverrideExtensionsFieldName) {
+		return nil, nil
+	}
+	extensionsCfgC, err := otelOverrideCfg.Child(outputOtelOverrideExtensionsFieldName, -1)
+	if err != nil {
+		return nil, err
+	}
+	extensionsCfgMap := make(map[string]map[string]any)
+	err = extensionsCfgC.Unpack(&extensionsCfgMap)
+	if err != nil {
+		return nil, err
+	}
+	return extensionsCfgMap, nil
+}
+
 func BeatDataPath(componentId string) string {
 	return filepath.Join(paths.Run(), componentId)
 }